The present invention relates to a faucet for a hydraulic system, of the type comprising an extractable cartridge mounted in the body of the faucet and containing a first stationary plate and a second rotatable plate in contact with the first one under the control of a handle, the said two plates being interposed between an inlet pipe union and an outlet pipe union and being traversed by apertures in such a way that in the position in which the apertures of the two plates do not match with one another the flow is intercepted, in the position in which the apertures completely match with one another the maximum flow passage takes place, and in intermediate positions a flow is obtained which is adjustable at will.
In a known type of faucet of this kind, each plate is traversed by two diametrically opposed apertures, wherefore the angular displacement of the handle between the interception and the largest flow positions is of 90.degree.. This imparts a poor sensitivity to the faucet and renders it necessary to use a costly fine toothing coupling to allow locking the handle in the correct position. Furthermore, in this faucet the cartridge is screwed in the body and requires a machining which is expensive because of the small tolerances required. The plates have to be held in mutual contact by means of a preloaded spring which is in its turn retained by a snap ring, which renders more complicate the construction and the disassembly operations of the cartridge. Special small nets have to be introduced into the apertures of the rotatable plate to attenuate the noise of the flow. Because of these conditions set forth hereinabove the faucet results in being expensive and relatively difficult to assemble and disassemble, and in addition it can be used only in case of particular configurations of the body and is not suitable for being used either with the normal faucets with an elongated body having a deep cavity or in the cases in which only particularly limited overall dimensions are acceptable.